Touch-Panel Device

1. A touch-panel device for detecting a touched position based on sensor measured values determined by a plurality of sensors coupled to electrodes serving as sensor terminals, the touch-panel device being configured to: determine, based on the sensor measured values for detecting a touched position in an X direction and a touched position in a Y direction, a width in the X direction and a width in the Y direction of an overlap area where a touched area and an electrode area of the electrodes overlap each other; determine, based on the width in the X direction and the width in the Y direction of the overlap area, a position of a center of the touched area; and calculate the position of the center of the touched area as the touched position, wherein, in a case where the touched area that includes a portion that extends off the electrode area in a first direction and another portion that overlaps the electrode area in the first direction, such that the portion of the touched area that extends off the electrode area is not detected, the position of the center of the touched area in the first direction is determined by subtracting, from a largest width in the first direction of the area where the touched area and the electrode area overlap each other, one-half of a largest width in a second direction, which is perpendicular to the first direction, of the area where the touched area and the electrode area overlap each other, and the first direction is one of the X direction and the Y direction, and the second direction is the other one of the X direction and the Y direction, and wherein: the width in the X direction of the overlap area where the touched area and the electrode area overlap each other is determined by multiplying a largest value of the sensor measured values on a Y axis by a preset value; and the width in the Y direction of the overlap area where the touched area and the electrode area overlap each other is determined by multiplying a largest value of the sensor measured values on an X axis by a preset value.

2. A touch-panel device for detecting a touched position based on sensor measured values determined by a plurality of sensors coupled to electrodes serving as sensor terminals and on positions of the electrodes, the touch-panel device being configured to perform a coordinate calculation process for determining the touched position by using parameter values for the positions of the plurality of electrodes, wherein the parameter values employed to perform the coordinate calculation process in a case where a periphery of a touch panel is touched are different from parameter values employed to perform the coordinate calculation process when a center of the touch panel is touched, wherein, in a case where the periphery of the touch panel is touched, the touched position is determined based on electrostatic capacitance of one of the electrodes having a maximum electrostatic capacitance, which has increased due to the touch on the touch panel, of all the electrodes, and electrostatic capacitance, which has increased due to the touch on the touch panel, of another electrode next to said one electrode, wherein, in a case where the touched area includes a portion that extends off the electrode area and another portion that overlaps the electrode area, so that the portion of the touched area that extends off the electrode area is not detected, an overlap width of the touched area and the electrode area is determined based on electrostatic capacitance in an electrode having the largest electrostatic capacitance increased due to a touch among all of the electrodes, wherein the parameter values employed in a case where a periphery of the touch panel is touched are defined by coordinate values of both outer edges of an electrode having the largest electrostatic capacitance and an electrode adjacent to the electrode having the largest electrostatic capacitance, and the parameter values employed in a case where the center of the touch panel is touched are defined by a coordinate value of the center of all of the electrodes, and wherein, in a case where the portion that extends off the electrode area and said another portion that overlaps the electrode area extend off the electrode area in a first direction and overlap the electrode area in the first direction, the position of the center of the touched area in the first direction is determined by subtracting, from a largest width in the first direction of the area where the touched area and the electrode area overlap each other, one half of a largest width in a second direction, which is perpendicular to the first direction, of the area where the area where the touched area and the electrode area overlap each other, and wherein the first direction is one of the X direction and the Y direction, and the second direction is the other one of the X direction and the Y direction.

3. The touch-panel device according to claim 2 , wherein the parameter values for the positions of the plurality of sensors employed in the coordinate calculation process to perform the coordinate calculation process in the case where the periphery of the touch panel is touched are defined by coordinate values of both outer edges of two electrodes provided at an edge of the touch panel.

4. The touch-panel device according to claim 2 , wherein, in the coordinate calculation process performed to perform the coordinate calculation process in the case where the periphery of the touch panel is touched, the sensor measured values to be referred to are each assigned a predetermined weight.

5. The touch-panel device according to claim 4 , wherein the predetermined weight is varied in accordance with a touch size.

6. The touch-panel device according to claim 1 , wherein the touched area is in a shape which has a constant ratio of a width thereof in the X direction to a width thereof in the Y direction.

7. The touch-panel device according to claim 1 , wherein the touched area is one of the circular and oval in shape.

8. The touch-panel device according to claim 1 , wherein the touched area is circular in shape.

9. The touch-panel device according to claim 2 , wherein the touched area is circular in shape.

10. The touch-panel device according to claim 2 , wherein the touched area is circular in shape.